Rock crusher



-May 4, 1943. E. N. woon ROCK CRUSHER Filed Dec. 15, 1939 2 Sheets-Sheet l @mi @wf ATTORNEY;

Patented May 4, 1943 Ar-ENT oren-cr.

noci; cnUsHER Everett` N. Wood, Minneapolis, Application December 15, 1939, senalNQ. 309,387

e s Clarins. (c1. ca -5s) The present invention relates to rock crushers of. the reciprocating jaw type and more particularly to those having jaws driven from a rotatable shaft upon whicha ywheel is mounted.

Reciprocating jaw rock Crushers, as customarily made, include a pair of relatively movable rock crushing jaws which are inclined with reference to each other. As usually made, one of the jaws is flxedly mounted with reference to the frame and the other of the jaws is mounted for oscillatory movement with reference to the stationary jaw so that stone is crushed as it moves between the jaws.

According to the usual mode of construction, the movable Crusher jaw is arranged to be oscillated by an eccentric shaft which is normally provided with one or more heavy flywheels for storing kinetic energy. As rock moves through the Crusher, the oscillating jaw exerts crushing forces on the rock and fractures it. Occasionally, however, an extra hard stone imposes excessive stresses with the result that the parts are eX- cessvely deflected and breakage occurs.

According to the present invention, the fly- Wheels of a movable jaw rock Crusher are rotatably mounted with reference to the rotating shaft and a resilient torque-transmitting member is interposed between the flywheel and the rotatable shaft upon which itis mounted. As a result of this construction, when the rockcrushing jaws encounter an extra hard stone, the impact stresses are reduced due to the resiliency of the torque drive between thev energy supplying fly-Wheels and the rotatably driven shaft, and breakage of the parts is much reduced. Stated another way, in the improved construction of the present invention, a given size of part of the Crusher is enabled to withstand greater stress than in rock crushers of previous construction.

It is accordingly an object of the invention to provide a movable jaw rock crusher having a rotatable drive in which resilient torque-transmitting members are interposed. It is also an object of the invention to provide a rock crusher having a fly wheel mounted upon a rotatable shaft and a resilientl torque-transmitting means between the y wheel and the shaft.

It has also been discovered that in rock crushers of the movable jaw type driven from a rotatable shaft having one or more fly wheels mounted thereon, as the movable jaws encounter an excessive hard rock, the shaft is caused todefleet. In such rock Crushers having the fly- Wheels solidily mounted upon the shaft, the detengan@ nieuwe e nove tra flywheel .l

out of its normal plane, of. rotation thereby illducing large strainsf'due to the gyroscopic stability of the' flywheels. Although the shaft deflection is small, it is rapidly applied due to the inherent lack of resiliency ofthe material 'beir'i'g'crushedy and as a consequence,'the' vily\'1yl'1`eels`` shafts. and other crush'erfparts have frequently bee'nbroken. Accordingto.` the present invention, Vsuch gyroscopicy stresses are"redu`ced or "eliminated by mounting thefiiywheel upon the rotatable shaft in such a wayas to permit the ywheel to remain in its plane ofrotation v(which it has established dueto gyroscopicforces), regardless of instan taneous'denection lof the shaft upon whichthe flywheel is mounted. ByV mounting -tliie flywheel in this irianner, the tendencyv of the deflecting shaft to move thel flywheel'out of its established plane of. rol-,ation is"el-irngi,nated and asa conse'- quence, the flywheelcontinuesv to rotate in its established plane regardless of instantaneous deflections ofthe shaft on whichit is mounted. 'It is, therefore, an'add'itional'object `of the invention to provide afro'ck` crushing device on which the flywheel is mounteds'o as .to permit the shaft carrying the flywheel todeflect without correspondingly moving the iiywheel Vthereby to minimize` or eliminate forces due to gyroscopic effects. t

Another object of the invention is the provision of improved shielding an oscillatable crusher Yfor preventingthef ingress of stone and dirt to certainY Crusher parts such' as', the toggle plate and tgglepiate bearing.

Other and further objects of the invention are those inherent inthe invention herein illustrated, desenpedand maimed.'

'I he invention isI illustrated with reference to the drawings in which Figure l is a lside elevationpartly in section of a movable jaw' lrock Crusher made in accordance with'the present in- Venue@ Figure 2 is an end elevation partly in section of the rock crusher made irac'cordance'with- `the present invention. The flywheel sectionof'Figure 2 is taken along'the lin'efZ-,-Z of Fig-ure 3.

Figure 3 is a side elevation partlyin section taken Ain the direction farrws'jSM-NS of Figure 2, the sectional pi'mti'on,ofjfi'g'ure beingalong Figui 2l is a fragmentary sketch along the line Aff-ll of Figure V3'.

Figure. 5^I is" aA fragmentary sectional View of a modified form nywhel useful in the/'present in'- venp.

'fllierock lerusher of the present invention in;

end wall I4 inclines outwardly at the top and is The interior cavity of the i provided with an internal flange 24. At the lower edge of Wall I4, there is an internal flange I8 which forms a V-notch.

Adjacent the wall I4, there is positioned a crusher jaw which rests against the integrally formed flange I8 at the lower edge, and is retained at the upper edge by means of a wedge' s plate 22. The wedge plate is drawn inwardly yin the space between flange 24 and the chamfered upper edge I9 of the crusher jaw 20 by means of bolt 23.

Within the crusher space, there is a pitman arm generally designated of heavy `Ir-beam construction. The pitman arm has an integrally formed retained notch 3| at its lower edge which serves to retain a movable crusher jaw 3.2. The upper edge of the jaw 32 is retained in place by means of a wedge strip 34, which is retained in place by bolt 35. At the lower rear portion of the pitman arm 30, there is provided a large V- notch 31, extending throughout the width of the pitman arm. The notch 31 is shaped to receive a chrome-manganese wear block 38 having a curved sector 39, which in turn receives the similarly curved edge of a toggle plate 40. The toggle plate extends toward the wall I3 of the crusher frame, and rests against an adjusting wedge block 42, the latter being provided with a curved notch 43 for receiving the rear edge of the toggle plate. The toggle plate is slightly curved and is provided with weakening holes 4I so that it will break when tramp iron or the like comes between the Crusher jaws. The wedge block 42 is mounted for movement to the right and tothe left as shown in Figure 1 upon pairs of rails 45 and 46, one pair of rails being mounted upon the inside of wall II, and the other upon the inside of wall I2. The rear part of block 42 is provided with awedging surface 50, which cooperates with a similarly shaped surface 5| of vertically movable Vwedging block l52. The wedging yblock 52 is Varranged to be moved upwardly by means of an adjusting bolt 55, the latter being adjusted by mechanism generally designated 6|),having an adjusting handle 6|. As the handle 6| is moved, the bolt 55 is drawn upwardly withlthe result that block 52 is likewise drawn upwardly and due to the slanting surface 5I imposes upon the block 42- a movement to the left as shown in Figure 1.` The wedge block 42 in turn moves the toggle plate to the left and as a result swings the lower edge of the toggle arm 30 to a position closer to the stationary crusher jaw 28.

The entire lower end o f the pitman arm 30 is drawn in the direction of arrow 63 by means of a heavy spring 65, which is attached to the pitman arm by means of bolt 66. The right-hand end 61 of the spring is attached to the hooked member 68 while the left-hand end 69 vof the spring is attached to the member lo, the latter being mounted for adjustable movement by means Vof bolt |I and nuts '12.` Thus, as'the bolt 18 is drawn to the right as shown in Figure 1,

the spring 65 is compressed and a force in the direction of arrow 63 is imposed upon the lower end of the pitman arm 3U.

Referring to Figures 1 and 2, it will be noted that the side members |I and I2 of the frame extend upwardly and form bearing pads generally designated and 8| in which there is rotatably mounted a shaft generally designated 85. In each of the bearing pads, there is a pair of tapered roller bearings generally designated 86. The bearings 86 are held in a bearing retainer 81 and are encased against the intrusion of dust by means of a cap 88. Between the bearing pads 89 and 8|, the shaft 85 is provided with an eccentric portion 90, on each end of which there is mounted .another tapered roller bearing 9|.A .The bearing 9| is held within a bearing retainer- 92, which is in turn bolted to the upper hollow portion 93 of the pitman arm. The upper end of the pitman arm is thus moved due to the eccentricity of the shaft and the movable crusher jaw 32 is accordingly displaced toward and' away from the stationary jaw 20.

It will be noted that the space betweenbearings 86 and 9| is lled by a flange collar` 94 and a collar 94a which are separate pieces. By making these parts separate,` each is concentric. They may be made inexpensively as compared with the oost of a single piece having an eccentric portion at 94.

The outer extending ends |80 and IGI of theV shaft 85 are provided with flywheel assemblies generally designated |02. The assemblies |02 include a hub portion generally designated |06, which is keyed to the shaft 85 at |01 and an outer flywheel member generally designated |94. The hub |05 has a bearing surface |88 upon which the hub portion of the flywheel memberIIlfl is rotatably mounted. The hub |05 has an outwardly extending flangev |09, which is curved over as shown at H0, where it meets a circular flange on the web |I2 of the flywheel portion |94.

Referring to Figure 3, it will be noted that the web I I2 of the outer flywheel part |94 is provided with eight lugs I3, which extend from near the inner circular flange I. The lugs |"I3 'are spaced apart from each other and form a cavity. The hub part |06 also has sets of lugs ||6,.fourV in number, which are formed Vintegrallyfupon the portion |09 of the member |06. The lugs ||3 (of the flywheel part |04) and the lugs I I6 (of hub part IBS) voverlap when assembled, the lugs IIS being assembled so as to fall in the cavities defined by the lugs II3. The width (thickness) of the lugs ||6` is less thanthe width of the cavity between the lugs H3, and the intervening space is illled with rubber blocks ISL "The rubber blocks are preferably made of rubber having a hardness of from 50 to 100 as determinedtby a durometer, which hardness approximates that of' tread rubber of automotive tires. The'blocks are'- preferably molded with holes* |20, and are made slightly over-sizeso that they are initiallyY under slight compression in their assembled condition` The hub portion of the outer flywheel member |04 is provided with a hole Ia held upon the bearing surface |98 of the inner flywheel member by means of a plate |22 and cap screws [2.3.

in' stung the nywheerpart ist upon hub me;

care isY taken to provide a llt Vso that the il'ywheel may, under certain conditions, run'in a plane which is not -at right angles to the axis'wof, shaft 85.l Theleast expensive way Iof accomplishing this .is to machine the h ub part los cylindrical and to' provide hole I98a in the flywheel with'a slight taper running throughout most of the length of the hole. Thus, near the end |25 the hole |0805 may have a contact t with cylindrical bearing part |08 for length of about 1/2 to 1 inch, and may then taper outwardly so that near the point |25 there is a clearance of from one-half to three thousandths of an -inch every inch of diameter of hub |98, the amount vdepending upon the calculated deflection of shaft .35 under most extreme conditions .of loading. The Vportion of the flywheel assembly is thus permitted to pivot about the tight fitting part |25 as will be explained below. In the drawings .the taperof hole 1| 38a is greatly .exaggerated for purposes of illus tration.

The collar |22 serves to hold the portieri E54 of the flywheel on the hub |33 and initially ,to place the rubber blocks iISl in a state of com-` pression. 'Ihe rubber blocks H9 react against the flywheel |34 and normally hold against collar |22 and hence in a plane at right angles tothe axis ofshaft 35. A space of about le to 1/8 inch is allowed between the flange! I5 of hub 33 and the flange III of flywheel member |33 so as to permit rocking motion of the latter.

During rock crushing operation of the device, rock is dumped into the Crusher between the stationary jaw 20 and the movable jaw 32, and the diameter of each rock particle is reduced as the rock passes downwardly until it passes through the nip portion 3l between the lower edge of the crusher jaws. `In the event an excessively hard stone such as a granite boulder or a quartalte block should enter the Crusher, the movement of the jaws is momentarily much slowed down or even momentarily stopped, and as a result `the rotatable shaft 85 is likewise momentarily slowed down or stopped. The parts are all placed under heavy strain and being elastic, they deform under the force induced by the heavy flywheel.

The flywheel, however, may overrun slightly as it compresses one set of the rubber blocks H9 against the lugs H3 and consequently, vthere is gradually built up a force sufficient to crush the rock. The rate of application of stress is theree fore distributed during the time that the rubber block is being compressed and the impact load accordingly greatly decreased.

As the stress increases in the Crusher jaws, the shaft 85 and other parts, the portion 35 of the shaft, between bearings 80 and 8| is deflected laterally, thus producing a slight bowing of the shaft, and consequently, the outer ends |30 and i0! are likewise deflected as the shaft-assumes the bowed condition. All the Ywhile this is happening, the shaft and flywheels are rotating and due to gyroscopic forces, the flywheels |52 tend to remain in the plane in which they were rotating. In ordinary crushers inv which the flywheels are xed on-the shaft, there is a severe strain set up as the bowing shaft tries to move the flywheels out of this established plane of rotation, since there are combined the large instantaneous torque and bending forces in the shaft.

In the present invention, however, the flywheels |02 are mounted so that they may, without `undue force, be moved out of their normal place at right angles to the shaft 05, due to the clearance between the bearing portion |00 ofthe hub |06 and the hole I08a of. the outer flywheel portion |04, and due to the provision of clearance at the surface |25. Asa consequence, asthe shaft 85 deilects under load, it does not move the flywheel parts |04 .out of their established planesof=ro tation,` even though ;the flywheel Lpartsl |04 @give 1 uptheir velocity energy (as torque) to the shaft, through the rubber block connection. ,'I-Ience, the instantaneous loading and flexing ,of `shaft d oes not impose lexcessive stresses uDQn the web IIZ and upon the shaft near hub |06 as ,would bethe case if the flywheels |02 were solidly VConnected to the shaft 85.

As V,therock fractures, the load upon the `Crusher is released, and crusher jaw 32 then being free to move toward the stationary jaw 20. As va result, the stored-up energy in Y,the rotatable shaft, which is bowed due .to Acrushing forces and also twisted due :to the torsional load thereon, and the stored-up .energy of all of the -remaining stressed parts of the cruSher, including that stored in -the rubber blocks IIB, are all instantaneously released, and the shaft 8,5-hence1tends to overrun the flywheel part |04. As the shaft ,thus overruns, the lugs IIB tend to compress the opposite set of the rubber blocks I I9, and the instantaneous overrun of the shaft 85 is thus gradually decreased without ,imparting excessive forces on the various part-s.

Figure 5 is an illustrationof the modified form of flywheel construction -in which a spherical bearing is provided between the hub portion and therflywherel portion in order to facilitate operation of the flywheel in a plane which is not -at right angles to the shaft l85. In the modied form of the invention, there is mounted upon the shaft 85 a hub portion generally designated |30, consisting of two outer flange plates I3 |-.-|3 I, which-are somewhat ksimilar to vthe hub portion .|06 withthe extending flange part |09-'I I0 of the type shownin -Figure 2. Between the parts |3||3|, there is positioned an inner hub |32 having a spherical surface |33. The three hub parts, namely, the part |33 and the outer parts I3 ||3I are held together in immovable relationship by a plurality of through .bolts |35 andthe three constitute a unit which is `keyed-to the shaft by means of key |31.

Each of the outer portions I3 I is provided with an outer marginal flange |38'having an inturned portion |39 at its edge, and an inner flange |40. In the space between the outer and inner portions |39 andlllll0lrespectively, there is an annular space in .which there are positioned a plurality of radially extending lugs |4| similar to the lugs ||.6 of the flywheel shown in Figures 2 and 3. Journalledyupon the spherical seat |33 and held between theportions I3Iv-there is mounted an outer flywheel member generally designated |50. This member is divided along the line I5! for purposes of assembly, and the divided parts |52 and |53 are held together by a plurality of bolts |54.

Thefpart |53 is provided with an inner flange |54 and an-outer flange |55, andthe part |52 is `provided with an inner flange |51 and an outer Yflange |58. The annular space between the inner ,ilangel andthe outer flange of part |53, and

the v similar annular space between the yinner ilange|5`| andthe outer flange |58 of part |52 isv sectored by a plurality of webs |60. The webs I4I of the outer members |.3I are positioned so as to fall within the spaces divided by the webs |60 of the flywheel portion |50 in the same manner as that shown in Figure 3, and the interven- `ing spaces-filled with rubber block in the fashion shown in Figure 3.v

The member |52 extends outwardly and forms webs or spokes at |63 and is provided with an outer flywheel face |64; which may, if "desired, be crowned at |65 to receive a driving belt.

r:Inasseniblingthe: ilywheelshown vin' Figure =5,

the spherical hub portion |32 is first inserted into the spherical bearing hole of part |52. Then the part |53 is assembled against part |52 and the bolts |56 are drawn tight. This holds the outer portion |50 of the flywheel on the spherical seat |32, but in the thus assembled condition, the outer iiywheel member |50 is movable under light force upon the spherical bearing part |33. 'I'he rubber blocks are then inserted in the cavi-'- ties formed by webs |4| ofthe inner ywheel member |50, and the outer parts |3||3| are arranged so that their webs |60 will come between the pairs of rubber blocks. I'he bolts |35 are then drawn tight so as to place the rubber blocks in an initial state of compression. The axial dimension of the member |32 is made sufficient that clearance of lg to 1A; of an inch will be provided at the division line |58 between the outer flywheel members |3| and the inner flywheel member |50.

As thus assembled, the flywheels part |50 is connected for torque transmission with the hub assembly |30, but part |50 may be deflected out of the plane at right angles to shaft 85. As the iiywheel rotates, it will establish (or tend to maintain) its plane of rotation at right angles to the shaft 85. VDuring rock crushing, as previously explained, when the shaft 85 is laterally deflected and thereby assumes a somewhat bowed condition the spherical seat |33 of the inner member will rotate angularly with reference to the outer iiywheel member |50, even though at the same time member |50 produces a rotative torque upon the members |3|| 3|, and consequently upon the shaft 85 by virtue of the rubber block connections between the flywheel members |50 and |30. Due to inherent gyroscopic forces upon the flywheel member |50, it will continue to rotate in its established plane of rotation regardless of deflection of shaft 85, but at the same time, will deliver kinetic energy (as a rotative torque) to the shaft 85 through the flexible rubber block connection.

In the crusher shown in Figure 1, there is provided a rock shield member |70, which extends upwardly from the frame portion I3 to within a short distance of the rear face of pitman arm 30 as shown at It is usually desirable to provide ka flexible tip such as tip |12 between the rock shield and the pitman arm. This may desirably be made of flexible belting or the like. The rock shield prevents small chips of rock and dust from working down into the space behind the crusher jaws and interfering with the action of the toggle plate 40 in wear block 38, at which t place the bearing pressures are exceedingly high and the bearings must therefore be maintained in as good condition as possible inrorder to prevent undue wear. The exclusion of dustvand rock chips also facilitates free action of the Wedge blocks 42 and 52 for adjusting the toggle plate 40.

It will be noted that due to the fact that the contact seat between the toggle plate and wedge block 42 is at an elevated position as compared with the contact seat between the toggle plate and the wear strip 38 of the pitman arm, the lower end of the pitman arm and the adjacent portion of the crusher jaw 32 is caused to move toward the stationary jaw 20, and thus produces a crushing action at the lower or nip portion of the jaws when the eccentric portion 9| of the shaft 85 is moving through the sector of rotation defined by arrow |80, even though at the same time, the upper portion of the pitman arm is movingupwardly and'away from the stationary Cil' crusher jaw. During the other sector of the turn generally indicated by the arrow |8|, the upper portion of the crusher jaw 32 is moved towards the upper portion of the stationarj7 crusher jaw 20, and thus produces a crushing action on the large stones at the upper or entrance portion 0f the jaws. In this way, the crushing action is distributed throughout a considerable portion of each complete revolution of the crusher jaw, and the working forces upon the crusher jaw are accordingly decreased for a given output of the crushed jaw. This arrangement is a desirable feature of the invention inasmuch as the capacity of the machine for a given stress upon the crusher parts is accordingly increased.

Entirely by way of example and without any intention of limiting the broader aspects of the invention, it may be stated that in a crusher having a jaw width of 24 inches and a maximum opening (distance between the jaws) of 10 inches (known as a 10 inch X 24 inch crusher), the shaft is made approximately 5 and 11e inches in diameter on the ends |00 and Il, and is approximately 7 inches in diameter at the eccentric portion 0|, the eccentricity being approximately 5/8 of an inch. A crusher of this type may desirably be provided with iiywheels having a total weight of 1 ton each and an outside diameter of approximately 50 inches, although 36 inch flywheels may also be used.

When operating at a speed of approximately 250 R. P, M, and provided with an adequate power supply (approximately 75 horsepower), it is possible to crush approximately 20 cubic yards of hard granite rock per hour and reduce the size of the stone from an average of 10 inches maximum dimension to l inch maximum dimension.

Many obvious variations may be made without departing from the spirit of the invention illustrated, described and claimed. Thus, in respect to the rubber torque-transmitting blocks, the rubber may be positioned nearer the rim than illustrated, or may be made of different size than that illustrated. Likewise, the number of blocks used may be less than 8 or more than 8 depending upon the amount of load carried and the type of rubber used. Likewise, the dimensions of the crusher may be widely varied to satisfy the particular conditions under which the crusher is used, and the size of the ywheels, the horsepower input and other factors may be varied in any instance to suit the exigencies of the situation in which the crusher is used.

Likewise, either the resilient torque transmitting arrangement or the suggested arrangements permitting the ywheel to run in a plane not at right angles to the shaft may be used in the absence of the other since each contributes an independent stress reducing effect in addition to their combined restress reducing eiect.

These and other variations will be apparent to those skilled in the art and are intended to be within the scope of the invention herein claimed.

What I claim is as follows:

1. A reciprocating jaw crusher comprising a frame, a stationary crusher jaw mounted on said frame, a jaw mounted for movement relative to the frame and rotatable shaft means mounted on the frame and connected to the movable jaw for moving the jaw toward and away from the stationary jaw,V a flywheel mounted on said rotatable shaft for rotation relative thereto and for slight movement out of a plane at right angles to the axis of said shaft, said Iiywheel being formed with walls defining a cavity, a protrusion formed on the shaft extending into said cavity and rubber torque transmitting blocks between the protrusion and the cavity wall for transmitting torque forces from the protrusion to the walls.

2. A reciprocating jaw crusher comprising a frame, a stationary Crusher jaw mounted on said frame, a jaw mounted for movement relative to the frame and rotatable shaft means mounted on the frame and connected to the movable jaw for moving the jaw toward and away from the stationary jaw, a flywheel mounted on said rotatable shaft for rotation relative thereto and for slight movement out of a plane at right angles to the axis of said shaft, said flywheel being formed with a plurality of projections extending outwardly from its axis of rotation, said projections being spaced from each other, projection means on the shaft positioned to extend outwardly between the projections of the flywheel, and rubber blocks mounted in the space between the shaft projection means and the flywheel projections for transmitting torque forces between the shaft and flywheel.

3. A reciprocating jaw Crusher comprising a frame, a stationary crusher jaw mounted on said frame, a jaw mounted for movement relative to the frame and rotatable shaft means mounted on the frame and connected to the movable jaw for moving the jaw toward and away from the stationary jaw, a flywheel mounted on said rotatable shaft for rotation relative thereto and for slight movement out of a plane at right angles to the axis of said shaft, said flywheel being formed with a hub and web extending from the hub toward the rim; a circular flange extending axially with reference to the web and spaced from the hub, a plurality of spaced lugs on the web and extending axially with reference to the flywheel, said lugs dividing the space between the hub and circular flange into sectors, and a part formed on the shaft extending parallel to the flywheel web for substantially enclosing the space between circular flange and the hub, lugs on said part extending into the sector and rubber blocks in the enclosured sector spaces between the flywheel lugs and part lugs.

4. A reciprocating machine for repeatedly applying heavy pressure to work undergoing treatment comprising a frame, a reciprocating work member mounted on said frame for movement relative thereto, a support on the frame for holding the work undergoing treatment, a shaft rotatively mounted in spaced journals on the frame, said shaft being provided with an eccentric portion between the journals, a movable portion of said reciprocating work member being rotatively connected to the eccentric portion of the shaft, a

flywheel mounted on the shaft for slight movement from a plane at right angles to the shaft whereby the flywheel may maintain rotation in an established plane when the shaft bends transversely while rotating under load, said flywheel also being mounted for rotative movement relative to the shaft said flywheel being formed with a hub and web extending from the hub toward the rim; a circular flange extending axially with reference to the web and spaced from the hub, a plurality of spaced lugs on the web and extending axially with reference to the ywheel, said lugs dividing the space between the hub and circular flange into sectors, and a part formed on the shaft extending parallel to the flywheel web for substantially enclosing the space between circular flange and the hub, lugs on said part extending into the sector and rubber blocks in the enclosured sector spaces between the flywheel lugs and part lugs.

5. A reciprocating jaw rock Crusher comprising a frame, a rock crushing jaw mounted in stationary relationship on said frame, a shaft rotatably mounted on said frame, said shaft having an eccentric portion, another jaw mounted on said frame for movement relative thereto and connection means between the jaw and said eccentric portion of the rotatable shaft for reciprocating the movable jaw from the shaft as the shaft is rotated, a flywheel mounted on the shaft for rotation relative to the shaft and. for slight movement out of a normal plane at right angles to said shaft, and torque transmitting means connecting the flywheel and shaft including a shaft projection extending outwardly from the axis of the shaft adjacent the flywheel and acooperating flywheel projection positioned on the flywheel so as to be in the plane of rotation of the 'shaft projection and a tough rubber block between the ywheel and shaft projections for transmitting torque from one to the other.

6. The apparatus of claim 5 further characterized in that the space between the projections of the shaft and flywheel is substantially enclosed and said substantially enclosed space lled by the rubber block.

'7. The apparatus of claim 5 further characterized in that the space between the projections of the shaft and ywheel is substantially enclosed and said substantially enclosed space is lled by the tough rubber block, and further characterized in that said block is provided with an aperture for facilitating compression.

8. The apparatus of claim 5 further characterized in that said tough rubber block has a hardness of 50 to 100 as determined by a durometer.

EVERETT N. WOOD. 

